1097194-13-2Relevant articles and documents
Highly Diastereoselective Synthesis of Cyclic α-Aminophosphonic and α-Aminophosphinic Acids from Glycyl-l-Proline 2,5-Diketopiperazine
Ordó?ez, Mario,Torres-Hernández, Fernando,Viveros-Ceballos, José Luis
, p. 7378 - 7383 (2019)
This paper describes the first diastereoselective synthesis of cyclic α-aminophosphonic and α-amino phosphonic acids from glycyl-l-proline 2,5-diketopiperazine (S)-6 prepared according to the usual peptide coupling procedures. The highlights of this contribution is the chemoselective reduction of the carbamate-imide activated carbonyl group in the N-Boc 2,5-diketopiperazine (S)-11 to generate the unstable hemiaminals (1R,8aS)-12 and (1S,8aS)-13, followed by the highly diastereoselective nucleophilic addition of trimethyl phosphite or dimethyl phenylphosphonite to the chiral carbenium ion (S)-5. Acid hydrolysis of the phosphonate and phosphinate functionalities with simultaneous cleavage of the tert-butyl carbamate protecting group led to the target compounds. The high diastereoselectivity in the nucleophilic addition of trivalent phosphorus to the chiral carbenium ion (S)-5 is in agreement with our precedent reports.
Electrogenerated chiral cationic glycine equivalents - Part 1: The 6-methoxy derivative of cyclo(L-Pro-Gly)
Kardassis, Georgios,Brungs, Peter,Steckhan, Eberhard
, p. 3471 - 3478 (1998)
The cyclic N,O-acetal cyclo(L-Pro-Gly(OMe)OMe (8) has proved to be an effective chiral electrophilic glycine equivalent which is applicable in nucleophilic substitution reactions not only under Broenstedt acid catalysis but also under Lewis acid catalysis with excellent diastereoselectivities. This chiral building block can easily be obtained by electrochemical methoxylative decarboxylation of the cyclic dipeptide 6 generated from L-proline and aminomalonic diester. Thus, enantiomerically pure D-allyl glycine has been generated.
N-Terminal Selective C?H Azidation of Proline-Containing Peptides: a Platform for Late-Stage Diversification
Allouche, Emmanuelle M. D.,Simonet-Davin, Rapha?l,Waser, Jerome
supporting information, (2022/02/25)
A methodology for the C?H azidation of N-terminal proline-containing peptides was developed employing only commercially available reagents. Peptides bearing a broad range of functionalities and containing up to 6 amino acids were selectively azidated at the carbamate-protected N-terminal residue in presence of the numerous other functional groups present on the molecules. Post-functionalizations of the obtained aminal compounds were achieved: cycloaddition reactions or C?C bond formations via a sequence of imine formation/nucleophilic addition were performed, offering an easy access to diversified peptides.
Clickable coupling of carboxylic acids and amines at room temperature mediated by SO2F2: A significant breakthrough for the construction of amides and peptide linkages
Wang, Shi-Meng,Zhao, Chuang,Zhang, Xu,Qin, Hua-Li
, p. 4087 - 4101 (2019/04/30)
The construction of amide bonds and peptide linkages is one of the most fundamental transformations in all life processes and organic synthesis. The synthesis of structurally ubiquitous amide motifs is essential in the assembly of numerous important molecules such as peptides, proteins, alkaloids, pharmaceutical agents, polymers, ligands and agrochemicals. A method of SO2F2-mediated direct clickable coupling of carboxylic acids with amines was developed for the synthesis of a broad scope of amides in a simple, mild, highly efficient, robust and practical manner (>110 examples, >90% yields in most cases). The direct click reactions of acids and amines on a gram scale are also demonstrated using an extremely easy work-up and purification process of washing with 1 M aqueous HCl to provide the desired amides in greater than 99% purity and excellent yields.
